It is well known to change the planform, via wing configuration changes, to achieve varying performance objectives for aircraft. For example, modern combat planes have variable sweep wing geometries that are deployed according to immediate performance requirements such as subsonic cruising, take-off and landing, which will have a corresponding, high-aspect ratio wing geometry, as compared to supersonic flight, which will have a different corresponding geometry, such as fully-swept back wings to mitigate drag. Such combat planes include, for example, the Panavia Tornado, F-14 Tomcat and MiG-27. Being able to make significant geometric changes to an aircraft's wing during flight increases the flexibility and overall suitability of the aircraft for disparate missions or disparate parts of a mission. However, such wings are very complex, introduce complex control issues and are highly expensive and therefore inappropriate for unmanned air vehicles (UAVs).
Furthermore, there is significant interest in biologically inspired technologies. Avian and marine biological systems comprising aerodynamic or hydrodynamic surfaces provide useful insights into balancing performance requirements of air and marine vehicles in terms of, for example, the lift/drag ratio, roll, pitch and yaw control and stability.